In various communication systems, such as in wireless or cable communications, a synthesis channelizer processes multiple narrowband signals to produce a broadband multi-channel signal.
Methods for processing narrowband signals are known in the art. For example, various multi-channel transmitter architectures are described by Harris et al. in “Digital Receivers and Transmitters Using Polyphase Filter Banks for Wireless Communications,” IEEE Transactions on Microwave Theory and Techniques, volume 51, issue 4, April 2003, pages 1395-1412.
U.S. Pat. No. 8,610,514 describes a full spectrum modulator that processes a plurality of Cable TV (CATV) channels from separate paths. Each path has (i) a first filter for pulse shaping an input channel signal and up-sampling a channel frequency thereof, (ii) an interpolator for interpolating the output of the first filter to a common sample rate, and (iii) a decimator for centering the output of the interpolator on a predetermined channel bandwidth. An Inverse Discrete Fourier Transform (IDFT) processor receives channel signal outputs from the decimators. A Polyphase filter bank receives IDFT processed parallel channel signals from the IDFT processor. A commutator converts the processed parallel channel signals from the Polyphase filter bank to a single stream of data. A second filter up-samples the single stream of data to a fixed output sampling rate and low pass filters alias signals therefrom.